CHAPTER V 
WOODS 
Quite a number of drugs consist of the wood of woody plants; 
such drugs are quassia, red saunders, white sandalwood, and 
gualac. 
When studying woods it is necessary to observe the cross, 
tangential, and radial sections. Such sections of quassia are 
shown in Plates 105, 106, and 107. When studying these sec- 
tions it should be remembered that while the types of cells form- 
ing quassia wood are similar to the cells forming other woods, 
still their structure, arrangement, and amount will vary in a 
recognizable way in the different woods. 
CROSS-SECTION QUASSIA 
Plate ros is a cross-section of quassia. It has the following 
structure: 
Vessels. The vessels occur singly or in groups of two to 
eight cells. The cells are variable in size and shape. The 
walls are yellowish white and porous. 
Medullary Rays. The medullary rays vary from one to five 
cells in width. 
The medullary ray cells are radially elongated and the walls” 
are strongly porous. 
Wood Parenchyma. The wood parenchyma cells have thin, 
yellowish-white, angled walls. 
Wood Fibres. The wood fibres have thick, yellowish-white, 
angled walls. These cells are smaller in diameter than the 
wood parenchyma cells. 
RADIAL SECTION QUASSIA 
The radial section of quassia (Plate 107) is as follows: 
Vessels. The vessels appear as in the tangential section. 
Medullary rays. The medullary rays vary from ten to 
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